Christine Lagarde, managing director of the International Monetary Fund, wants world leaders who call themselves feminists to practice what they preach.

"I've heard so many leaders say, 'Oh, I'm a feminist,'" Lagarde told Richard Quest of CNNMoney. "To all those who have declared themselves feminists -- and I applaud them and I continue to applaud them -- let's make sure that we hold them to account and that they actually demonstrate what they preach."

The focus of the interview was International Women's Day, which takes place March 8. Lagarde said she was concerned that feminist rhetoric from some world leaders "does not necessarily match the practice and I don't really understand why."

"When you have women in any executive group, the results are better," she said. "When you have women join the labor force, it's better for growth. It improves the whole chemistry, and yet it is not happening fast enough. In some cases, it is not happening at all."

She said that many countries need to change laws before women can achieve equality. For example, she said that some countries tax by the family, which causes the second worker in the household -- usually the woman -- to be taxed at a higher rate. She also said that more countries should provide good child care services so women can work during the day.

Lagarde acknowleged to Quest that it's "a bit depressing" to still be falling behind in achieving equality for women.

"I think it will continuously be so, because there's an element of culture, there's an element of history," she said. "There is an element of biology and genetics about it, which we have to constantly fight against and we should do so because I think it leads to improvement of the entire community."

Lagarde has said, in an IMF video two years ago, that IMF research shows that women's participation in the workforce leads boosts economies. But there are many legal barriers to them working in many countries, including the tax system, and the lack of maternity and paternity leave.